This invention relates to the field of lighting and illumination. More particularly, this invention is a technique to use the wetting phenomenon of liquids to encapsulate a light emitting diode (LED).
Since the development of the incandescent light bulb, electric lighting has become widely adopted and is considered one of the inventions which has had the most profound impact on human society. Lighting allows people to do many activities in the night hours which they would otherwise not be able to do without such lighting. Modern society depends on electric lighting.
LEDs have recently been growing in popularity for electric lighting because of it's overall lower energy consumption and it's longevity compared to other electric lighting. LEDs are used in a growing variety of applications.
Despite the increasing popularity of LEDs, there continues to be a need for improvements in LED technology. For example, LEDs are typically packaged so they can be used. Packaging is the process where an LED chip is provided with the necessary mechanics for electrical connection, mechanical stability, thermal dissipation, and environmental protection.
In a representative packaging process, the LED is encapsulated using an encapsulant material such as silicone to enclose and protect the LED chip and its associated components. The encapsulation can also useful to increase light extraction or suspend particles near the LED for various purposes. The encapsulant material can be shaped in a molding process to form optical elements to control the light distribution from the LED chip. However, the act of dispensing or injecting the silicone typically causes air bubbles inclusions resulting in rejects. The molding process uses a precision mold and time in the mold to cure the encapsulant, this decreases manufacturing throughput.
Therefore, there is a need for improved techniques of encapsulating LEDs.